[Genome] Questions about GNF Atlas2 Table

[He Wenjun]

Dear Sir or Madam,

I'm using the GNF Atlas2 data  from your Table Browser to do some research.

I am confused about some procedures taken to build the database, and I can't
find the relevant information anywhere.

For example,
1). how did you relate the data from GNFAtlas to the USCS Known Gene?
2). Why the number of items in hgFixed.gnfHumanAtlas2Median is less than
gnfAtlas2?

3). I wanna select some highly expressed tissue-specific genes. What cut-off
value or method should I take according to the expScores?

If it is possible, could you please give me a detailed describe
about processes taken to build the GNF Atlas2 database? That would help me a
lot.

Your help wil be appreciated very much.

Yours sincerely,
Wenjun He